Spectroscopy and mechanical modification of single strain-induced quantum dots

We report the observation of very sharp lines in the photoluminescence spec tra of single strain induced GaAs quantum dots. By removing self-assembled GaSb stressors from the sample surface with an atomic force microscope, we have demonstrated that only the largest GaSb stressors are responsible for the sharp strain-induced quantum dot lines. Spectral line shifts art: obser ved as the quantum dot potential is tuned by modification of the large stre ssors. The variation of the spectra with laser power density is consistent with emission from multiexciton complexes and excited dot orbital slates.